Results of COVID-19 Vaccine Effectiveness Studies: An Ongoing Systematic Review Weekly Summary Tables Updated July 22, 2021
Prepared by: International Vaccine Access Center,
Johns Hopkins Bloomberg School of Public Health and
World Health Organization
For comments or questions, please contact: Anurima Baidya at [email protected] or
Karoline Walter at [email protected].
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TABLE OF CONTENTS 1. Summary of Study Results for Post-Authorization COVID-19 Vaccine Effectiveness 3 1.1 Inclusion criteria for VE studies 16 1.2 VE Studies that do not meet criteria 16 2. Summary of Study Results for Post-Authorization COVID-19 Vaccine Effectiveness Against Transmission 20 3. Vaccine Impact: Summary of Ecologic Study Results for Post-Authorization COVID-19 Vaccine Products 22
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1. Summary of Study Results for Post-Authorization COVID-19 Vaccine Effectiveness#
(Detailed methods available on VIEW-hub Resources page: https://view-hub.org/resources)
# Reference (date) Country Design Population
Dominant Variants (Alpha=B.1.1.7 Beta=B.131 Gamma=P.1 Delta=B.1617.2)
History of COVID
Vaccine Product
Outcome Measure
1st Dose VE (95%CI)
Days post 1st dose
2nd Dose VE (95% CI)
Days post 2nd dose
Max Duration of follow up
after fully vaccinated
69 Lopez Bernal et al* (July 21, 2021)
UK Test-negative case control
19,109 cases and 171,834 test negative controls among UK adults aged 16+
Alpha^
Excluded BNT162b2 Symptomatic COVID-19
47.5 (41.6–52.8) 21+ (up to day before dose 2)
93.7 (91.6–95.3)
14+ ~17 weeks
AZD1222 Symptomatic COVID-19
48.7 (45.2–51.9) 74.5 (68.4–79.4)
Delta^
BNT162b2 Symptomatic COVID-19
35.6 (22.7–46.4) 88.0 (85.3–90.1)
AZD1222 Symptomatic COVID-19
30.0 (24.3–35.3) 67.0 (61.3–71.8)
68 Butt et al* (July 20, 2021)
USA Test-negative case control
54,360 propensity-matched pairs of veterans
Original and Alpha ⴕⴕ
Excluded BNT162b2 and mRNA-1273
Documented infection
85.0% (84.2-85.8)
0+ 97.1(96.6-97.5)
7+ ~6.5 weeks
BNT162b2 Documented infection
84.0% (82.7-85.1)
96.2(95.5-96.9)
mRNA-1273 Documented infection
85.7% (84.6-86.8)
98.2(97.5-98.6)
67 Layan, Maylis et al (July 16,2021)
Israel Prospective cohort
215 index cases and 687 household contacts from 210 Israeli households
Original and Alpha¶
Included BNT162b2 Documented infection among HHCs vaccinated and not isolated (relative to HHCs not vaccinated and not isolated)
— — 81(60-93) 7+ ~12 weeks
66 Balicer et al (July 12,2021)
Israel Prospective Cohort
21722 pregnant Israeli women
Original and Alpha^
Excluded BNT162b2 and mRNA-1273
Documented infection
67(40-84) 14-20 96(89-100) 7-56 ~18 weeks 71(33-94) 21-27
Symptomatic COVID-19
66(32-86) 14-20 97(91-100) 76(30-100) 21-27
Hospitalization — — 89(43-100) 65 Butt et al
(June 22,2021) Qatar Test-negative
case control 1255 pregnant Qatar women
Alpha and Beta^ Excluded BNT162b2 and mRNA-1273
Documented infection
40.3(0.0-80.4) 14+ 67.7(30.5-86.9)
14+ ~17 weeks
64 Prunas et al (July 16, 2021)
Israel Retrospective cohort
253,564 Israeli individuals
Original and Alpha¶
Unknown BNT162b2 Documented infection
— — 80.5(78.9-82.1)
10+
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from 65,264 households with at least 1 infected individual and at least 2 members
63 Whitaker et al (July 9,2021)
UK Prospective cohort
5,642,687 UK patients reporting to 718 English general practises
Original and Alphaψ
Included BNT162b2 Symptomatic COVID-19
48.6(27.9-63.3) 28 to 90 days
93.3(85.8-96.8)
14+ ~20 weeks
AZD1222 50.2(40.8-58.2) 78.0(69.7-84.0)
62 John et al (July 13,2021)
USA Retrospective cohort
40,074 patients with cirrhosis within Veterans Health Administration, propensity matched
Original and Alpha ⴕⴕ
Excluded BNT162b2 and mRNA-1273
Documented infection
64.8(10.9-86.1) 28+ 78.6(25.5-93.8)
7+ ~10 weeks
Hospitalization 100.0(99.3-100.0)
100.0(99-100)
COVID-19 related death
100.0(99.3-100.0)
100.0(99-100)
61 Bertollini et al (July 13, 2021)
Qatar Prospective cohort
10,092 matched pairs of Qatari adults arriving at an international airport.
Original, Alpha and Beta^
Included BNT162b2 and mRNA-1273
Documented infection
78(72-83) ~4 weeks
60 Goldshtein et al (July 12,2021)
Israel Retrospective cohort
15060 pregnant Israeli women
Original and Alpha¶
Excluded BNT162b2 Documented infection
54(33-69) 11-27 days ~5 weeks
78(57-89) 28+
59 Chemaitelly et al* (July 9, 2021)
Qatar Test-negative case-control
25,034 matched pairs of Qatari adults
Alpha^ Unknown mRNA-1273
Documented infection
88.2(83.8-91.4) 14+ days, prior to 2nd dose
100.0% (CI omitted since there were no events among vaccinated persons)
14+ 13 weeks
52,442 matched pairs of Qatari adults
Beta^ Unknown mRNA-1273
Documented infection
68.2(64.3-71.7) 96.0% (90.9-98.2)
4,497 matched pairs
Alpha and Beta^ Unknown mRNA-1273
Severe, critical or fatal disease
83.7(74.1-89.7) 89.5% (18.8-98.7)
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of Qatari adults
Symptomatic infection
66.0(60.6-70.7) 98.6% (92.0-100.0)
Asymptomatic infection
47.3(37.6-55.5) 92.5% (84.8-96.9)
Retrospective cohort
Qatari adults (2520 vaccinated and 73,853 unvaccinated, antibody-negative controls)
Alpha^ Excluded mRNA-1273 Documented infection
— 100.0% (82.5-100.)
14+ 13 weeks
Beta^ Excluded mRNA-1273 Documented infection
— 87.8% (73.4-95.5)
Variants of unknown status
Excluded mRNA-1273 Documented infection
— 93.5% (76.6-99.2)
58 Tenforde et al (July 8, 2021)
USA Test-negative case-control
1210 hospitalized adults in the US
Original and Alpha^
Included BNT162b2/mRNA-1273
Hospitalization 76.0(63.7-84.1) 14+ 86.9% (80.4-91.2)
14+ ~2 weeks
BNT162b2 — 84.3(74.6-90.3)
mRNA-1273 — 90.0(82.0-94.4)
Alpha^ Included BNT162b2/mRNA-1273
— 92.8(83.0-96.9)(
57 Jara et al (July 7,2021)
Chile Prospective cohort
10,187,720 Chilean adults
Alpha and Gamma^
Excluded CoronaVac Documented infection
15.5(14.2-16.8) 14+ days, prior to dose 2
65.9(65.2-66.6)
14+ 8 weeks
Hospitalization 37.4(34.9-39.9) 87.5(86.7-88.2)
ICU admission 44.7(40.8-48.3) 90.3(89.1-91.4)
Death 45.7(40.9-50.2) 86.3(84.5-87.9)
56 Nasreen et al (July 3, 2021)
Canada Test-negative Case Control
421073 community dwelling individuals
Non-VOC Unknown BNT162b2 Symptomatic infection
61 (54, 68) 14+ days 93 (88, 96) 7+ 18 weeks
Hospitalization or death
68 (54,78) 96 (82, 99)
mRNA-1273 Symptomatic infection
54 (28, 70)
89 (65, 96)
Hospitalization or death
57 (28, 75)
96 (70, 99)
AZD1222 Symptomatic
infection 67 (38, 82)
—
Alpha^ Unknown BNT162b2 Symptomatic infection
66 (64, 68)
89 (86, 91)
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Hospitalization or death
80 (78, 82)
95 (92, 97)
mRNA-1273 Symptomatic
infection 83 (80, 86)
92 (86, 96)
Hospitalization or death
79 (74, 83) 94 (89, 97)
AZD1222 Symptomatic infection
64 (60, 68) —
Hospitalization or death
85 (81, 88) —
Beta/Gamma^ Unknown BNT162b2 Symptomatic infection
60 (52,67) 84 (69, 92)
Hospitalization or death
77 (69, 83) 95 (81, 99)
mRNA-1273 Symptomatic infection
77 (63, 86) —
Hospitalization or death
89 (73, 95) —
AZD1222 Symptomatic infection
48 (28, 63) —
Hospitalization or death
83 (66, 92) —
Delta^ Unknown BNT162b2 Symptomatic infection
56 (45, 64) 87 (64, 95)
Hospitalization or death
78 (65, 86) —
mRNA-1273 Symptomatic infection
72 (57, 82) —
Hospitalization or death
96 (72, 99) —
AZD1222 Symptomatic infection
67 (44, 80) —
Hospitalization or death
88 (60, 96) —
55 Baum et al (June 28,2021)
Finland Prospective cohort
Two study cohorts: 901092 Finnish elderly aged 70 years and 774526 chronically ill aged 16-69 years
Original and Alpha^
Excluded BNT162b2 & mRNA-1273
Documented infection
45 (36-53) 21+ days 75 (65-82) 7+ 16 weeks
Hospitalization 63 (49-74) 93 (70-98) AZD1222 Documented
infection 42 (32-50) —
Hospitalization 62 (42-75) —
54 Israel Retrospective cohort
1.6 million members of
Original and Alpha¶
Excluded BNT162b2 Documented infection
— 93.0 (92.6-93.4)
7+ 14 weeks
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Saciuk et al (June 27, 2021)
Maccabi HealthCare HMO ≥16
Hospitalization — 93.4 (91.9-94.7)
7+
Death — 91.1 (86.5-94.1)
7+
53 Pawlowski et al.* (Jun 17, 2021) [Update to Feb. 18, 2021 preprint]
USA – Mayo Clinic
Retrospective Cohort
68,266 – propensity matched on, zip, # of PCRs, demographics
Original & Alpha ¥ excluded BNT162b2
Documented Infection
61.0% (50.8-69.2)
≥14, prior to 2nd dose
88.0% (84.2-91.0)
≥14 ~17 weeks (120 days)
Hospitalization — 88.3% (72.6-95.9)
≥14
ICU Admission — 100.0% (18.7-100)
≥14
mRNA-1273 Documented Infection
66.6% (51.9-77.3)
≥14, prior to 2nd dose
92.3% (82.4-97.3)
≥14
Hospitalization — 90.6% (76.5-97.1)
≥14
ICU Admission — 100.0% (17.9-100)
≥14
52 Young-Xu et al (July 14,2021) [Update to Jun 22 preprint]
USA Test negative case control
77014 veterans within Veterans Health Administration
Original and Alpha ⴕⴕ
Excluded BNT162b2 & mRNA-1273
Documented infection
58 (54-62) 7+ days up to dose 2
94 (92-95) 7+ ~8 weeks
Hospitalization 40 (27-50) 89 (81-93)
Death 55 (21- 74) 98.5 (86.6-99.8)
51 Mazagatos et al (June 17, 2021)*
Spain Screening method
8379 Long-term care facility residents
Original and Alphaⴕⴕ
Included BNT162b2 & mRNA-1273
Documented infection
50.5 (37.1-61.1) >14 71.4 (55.7-81.5)
>7 for BNT162b2 >14 for mRNA-1273
~10 weeks
Asymptomatic infection
58.0 (41.7-69.7) 69.7 (47.7-82.5)
Hospitalization 53.0 (25.7-70.3) 88.4 (74.9-94.7)
Deaths 55.6 (26.6-73.2) 97.0 (91.7-98.9)
50 Azamgarhi et al (June 17, 2021)* [Update to Azamgarhi et al below]
UK-London
Retrospective cohort
2235 HCWs working at one hospital
Original and Alpha£
Excluded BNT162b2 Documented infection
70.0 (6.0-91.0) >14 —
49 Gupta et al (June 16, 2021)*
USA Retrospective cohort
4028 HCWs in Boston, Massachusetts
Original and Alpha
Unknown mRNA-1273 Documented infection
95.0 (86-98.2) >14 days post dose 1 to 13 days post dose 2
—
48 Stowe et al (June 14, 2021)
UK TND Case-control
Patients seeking emergency care services with subsequent
Alpha included BNT162b2 Hospitalization 83% (62-93) 21+ to <13 days post dose 2
95% (78-99)
14+ ~20 weeks (but most much less) AZD1222 76% (61-85) 86% (53-
96) Delta BNT162b2 94% (46-99) 96 (86-99)
AZD1222 71% (51-83) 92% (75-97)
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hospitalization
47 Sheik et al (June 14, 2021)
Scotland TND Scottish population
Alpha Unknown BNT162b2 Documented infection
38 (29-45) 28+ 92% (90–93)
14+ ~20 weeks (but most much less) Unknown AZD1222 Documented
infection 37 (32-42) 28+ 73% (66–
78) 14+
Delta Unknown BNT162b2 Documented infection
30 (17-41) 28+ 79% (75–82)
14+
Unknown AZD1222 Documented infection
18 (9-25) 28+ 60% (53–66)
14+
46 Flacco, Maria et al* (June 10, 2021)
Italy Retrospective cohort
245,226 individuals
Original and Alphaⴕⴕ
Unknown BNT162b2 Documented infection
55(40-66) 14+ days 98(97-99) 14+ ~14 weeks
Hospitalization — 99(96-100) 14+ Death — 98(87-100) 14+
mRNA-1273 Documented infection
93(74-98) 14+ days —
AZD1222 Documented infection
95(92-97) 21+ days —
45 Skowronski et al* (July 9, 2021) [Update to June 9 preprint]
Canada TND ≥70 year olds living in community
Alpha Included BNT162b2 & mRNA-1273
Documented infection
67% (95% CI 57-75)
21+ — ~6 weeks
Gamma 61% (95% CI 45- 72)
21+
Non-VOC 72% (95% CI 58-81)
21+
44 Emborg et al. (June 2, 2021) [Update of Houston-Melms below]
Denmark Cohort 46,101 long-term care facility (LTCF) residents, 61,805 individuals 65 years and older living at home but requiring practical help and personal care (65PHC), 98,533 individuals ≥85 years of age (+85), 425,799 health-care workers (HCWs), and 231,858 individuals with comorbidities
original & Alpha¶¶ excluded BNT162b2 Documented infection
7 (-1-15)
>14 82 (79-84) >7 10 weeks
COVID-Hospitalization
35 (18-49) >14 93 (89-96) >7
COVID-Mortality
7 (-15-25) >14 94 (90-96) >7
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that predispose for severe COVID-19 disease (SCD)
43 Thompson et al* [updated on June 30,2021]
USA Cohort 3975 health care personnel, first responders, and other essential and frontline workers in 8 locations in US
Original Excluded BNT162b2 Documented infection
80 (60-90)
≥14 days post dose 1 to 13 days post dose 2
93 (78-98)
≥14 13 weeks
mRNA-1273 Documented infection
83 (40-95)
≥14 days post dose 1 to 13 days post dose 2
82 (20-96)
≥14
42 Salo et al (July 10, 2021) [Update to May 30 preprint]
Finland Retrospective cohort
HCW and their unvaccinated spouses
Alphaⴕⴕ Excluded BNT162b2 & mRNA-1273
Documented infection in HCW
26.8% (7.5-42.1)
2 weeks — *10 weeks since dose 1
Documented infection in HCW
69% (59.2-76.3)
10 weeks (combo of 1+2 dose recipients)
—
41 Khan et al (May 31, 2021)
USA Retrospective cohort
14,697 IBD patients in VA hospitals
Unknown Included BNT162b2 & mRNA-1273
Documented infection
-1% (-50-32) 14+ 69% (44-83)
7+ 14 weeks
Hospitalization/death
9% (-114-61) 14+ 49% (-36-81)
7+
40 Martinez-Bas et al* (May 27, 2021)
Spain Prospective Cohort
20,961 close contacts of confirmed cases
Alpha Excluded BNT162b2 Documented infection
21 (3-36%) 14+ 65 (56-73) 14+ 12 weeks
Symptomatic infection
30 (10-45) 14+ 82 (73-88) 14+
Hospitalization 65 (25-83) 14+ 94 (60-99) 14+ AZD1222 Documented
infection 44 (31-54) 14+ — n/a
Symptomatic infection
50 (37-61) 14+ —
Hospitalization 92 (46-99) 14+ — 39 Chung et al
(May 28, 2021)
Canada Test negative design case control
Adults in Ontario 53,270 cases 270,763 controls
Alpha (31%) Beta+Gamma (3%)
excluded BNT162b2 Symptomatic infection
59 (55-62)
14+ 91 (88-93)
7+ 15 weeks
Hospitalization and Death
69 (59-77)
14+ 96 (82-99)
0+
mRNA-1273 Symptomatic infection
72 (63-80)
14+ 94 (86-97)
7+
Hospitalization and Death
73 (42-87) 14+ 96 (74-100) 0+
Alpha specifically BNT162b2 & mRNA-1273
Symptomatic infection
61 (56-66) 14+ 90 (85-94) 7+
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Hospitalizationand Death
59 (39-73) 14+ 94 (59-99) 0+
Beta or Gamma specifically
BNT162b2 & mRNA-1273
Symptomatic infection
43 (22-59) 14+ 88 (61-96)
7+
38 PHE (May 20, 2021)
UK Test-negative case control
≥65 years Alpha excluded BNT162b2 Symptomatic infection
54 (50-58)
28+ 90 (82-95)
≥14
AZD1222 Symptomatic infection
53 (49-57) 28+ 89 (78-94) ≥14
37 Lopez-Bernal et al (May 20, 2021)
UK Test-negative case control
63,839 (58,253 controls, 695 Delta, 4891 Alpha cases)
Alpha excluded BNT162b2 Symptomatic infection
49.2% (42.6-55)
21+ days post dose 1
93.4% (90.4-95.5)
≥14
Excluded AZD1222 Symptomatic infection
51.4 (47.3-55.2) 21+ days post dose 1
66.1% (54.0-75.0)
≥14
Delta Excluded BNT162b2 Symptomatic infection
33.2 (8.3-51.4) 21+ days post dose 1
87.9 (78.2-93.2)
≥14
excluded AZD1222 Symptomatic infection
32.9% (19.3-44.3)
21+ days post dose 1
59.8% (28.9-77.3)
≥14
36 Ranzani et al. (updated Jul 21, 2021)
Brazil Test-negative case control
7950 matched pairs among 70+ year olds in Sao Paulo
Gamma Included Coronavac Symptomatic infection
10.5% (-4.4-23.3) ≥14
41.6% (26.9 -53.3)
≥14
~10.5 weeks
Hospitalization
18.5% (-1.0-34.2) 59.0 (44.2-69.8)
Death 31.6% (7.1-49.7) 71.4% (53.7-82.3)
35 Ismail et al. (May 12, 2021)
UK Screening method
13,907 ≥70 Alpha included AZD1222 Hospitalization in 70-79
84% (74-89%)
28+ —
Hospitalization I n 80+
73% (60-81%)
28+ —
BNT162b2 Hospitalization in 70-79
81% (73-87%)
28+ —
Hospitalization I n 80+
81% (76-85%)
28+ 93% (89-95%)
≥14
34 Pilishvili et al.* (May 14, 2021)
US Test-negative case control
HCP at 33 U.S. sites across 25 U.S. states
Unknown Excluded BNT162b2 & mRNA-1273
Symptomatic infection
82% (74-87) ≥14 days after dose 1 to 6 days after dose 2
94% (87-97)
≥7
33 Lopez-Bernal et al.* (May 13, 2021) [Update to Mar 1 preprint]
UK Test-negative case control
156,930 UK population over age 70
Alpha^ Included BNT162b2 Over 80 years: Symptomatic infection
— 79% (68-86)
≥7
Over 70 years: Symptomatic infection
61% (51-69) 28-34 days after dose 1 including some with dose 2
—
AZD1222 Over 70 years: Symptomatic infection
60% (41-73) 28-34 days after dose 1 including some with dose 2
—
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32 Angel et al.* (May 6, 2021)
Israel Retrospective cohort
6710 HCWs at a single tertiary care center in
Alpha¶ Excluded BNT162b2 Symptomatic 89% (83-94) >7 days after dose 1 to 7 days after dose 2
97% (94-99)
>7 days
Asymptomatic 36% (-51-69) 86% (69-97)
31 Abu-Raddad et al.* (May 5, 2021), with more granular 1 dose analysis here(July 8, 2021)
Qatar Test-negative case-control
Qatari adults Alpha & Beta^ Unknown BNT162b2 CC Alpha documented infection
65.5% (58.2-71.5)
15-21 days 90% (86-92)
≥14
CC Alpha severe/fatal infection
72% (32-90)
100% (82-100)
CC Beta documented infection
46.5% (38.7-53.3)
75% (71-79)
CC Beta severe/fatal infection
56.5% (0-82.8)
100% (74-100)
Retrospective cohort
Qatari adults Alpha & Beta^ Unknown BNT162b2 Cohort documented infection Alpha
— 87% (82-91)
Cohort documented infection Beta
— 72% (66-77)
30 Haas et al. * (May 5, 2021) [Update to Mar 24 preprint]
Israel Retrospective cohort
Israeli population ≥16 years
Alpha^ Excluded BNT162b2 Documented infection
— 95.3 % (94.9-95.7)
≥7 days
Asymptomatic infection
91.5% (90.7-92.2)
Symptomatic infection
97.0% (96.7-97.2)
Hospitalization 97.2% (96.8-97.5)
Severe/ critical hospitalization
97.5% (97.1-97.8)
Death 96.7% (96.0-97.3)
29 Corchado-Garcia et al. (April 30, 2021)
USA Retrospective cohort
24,145 patients in the Mayo Clinic Network
Original & Alpha¥ Excluded Ad26.COV2.S Documented infection
77% (30-95) ≥15 days —
28 Fabiani et al.* (Apr 29, 2021)
Italy Retrospective cohort
9,878 HCWs Unknown Excluded BNT162b2 Documented infection
84% (40-96) 14-21 days 95% (62-99)
≥7 days
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Symptomatic infection
83% (15-97) 94% (51-99)
27 Gras-Valenti et al.*(Apr 29, 2021)
Spain Case-control 268 Spanish HCWs
Original & Alpha¥¥ Included BNT162b2 Documented infection
53% (1-77) >12 days —
26 Tenforde et al.* (Apr 28, 2021)
USA Test-negative case-control
Hospitalized adults ≥65 years
Original and Alpha¥
Unknown BNT162b2 & mRNA-1273
Hospitalization 64% (28-82)
≥14 days after dose 1 to 14 days after dose 2
94% (49-99)
≥14 days
25 Menni et al.* (Apr 27, 2021) [Update to Mar 4 preprint]
UK Prospective cohort
Approximately 500,000 general population >16 years
original and Alpha£
Included BNT162b2 Documented infection (self-reported)
58% (54-62) 12-20 —
AZD1222 Documented infection (self-reported)
60% (49-68) 12-20
24 Goldberg et al. (Apr 24, 2021)
Israel Prospective cohort
5,600,000+ individuals ≥16
Original and Alpha^
Included BNT162b2 Documented infection
58% (57-59) >14 days after dose 1 to <7 days after dose 2
93%(93-93) ≥7 days
Hospitalization 69% (68-71) 94%(94-95) Severe disease 66%(63-69) 94%(94-95) Death 63%(58-67) 94%(93-95)
23 Pritchard et al.* (Jun 9, 2021) [Update to Apr 23 preprint]
UK Prospective cohort
373,402 individuals ≥16
Alpha & Original^ Excluded BNT162b2 Documented infection
66 (60-71) ≥21 days 80% (74-85)
≥0 days
Symptomatic disease
78 (72-83) 95 (91-98) AZD1222 Documented
infection 61% (54-68) 79% (65-
88)
Symptomatic disease
71 (62-78) 92 (78-97) 22 Vasileiou et
al.* (Apr 23, 2021) [Update to Feb 21 preprint]
UK – Scotland
Prospective Cohort (Person-time)
Scotland population: 5.4 million
Original & Alpha£ Excluded
BNT162b2
Hospitalization 91% (85-94) 28-34 days —
AZD1222 Hospitalization 88% (75-94) 28-34 days
21 Hall et al.* (Apr 23, 2021) [Update to Feb 21 preprint]
UK – SIREN study
Prospective Cohort (Person-time)
23,324 healthcare workers
Alpha^ Excluded BNT162b2 Documented infection
72% (58-86) ≥21 86% (76-97)
≥7
20 Mason et al. (Apr 22, 2021)
UK - England
Case-control 170,226 80-83 year-olds
Alpha^ Excluded BNT162b2
Documented infection4
55% (40-66) 21-27 70% (55- 80)
35-41
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Hospitalization4
50% (19-69) 21-27 75% (52-87)
35-41
19 Bjork et al. (Apr 21, 2021)
Sweden Retrospective cohort
805,741 Swedish adults aged 18-64 years
Original & Alpha^ Unknown BNT162b2 Documented infection
42% (14-63) ≥14 86% (72-94)
≥7
18 Gobierno de Chile (Apr 16, 2021)
Chile Retrospective cohort
10,500,000 individuals >16 years under the national health fund
Original, Gamma, and Alpha££
Unknown CoronaVac Symptomatic infection
16% (14-18) ≥14 67% (65-69)
≥14
Hospitalization 37% (32-39) ≥14 85% (83-87)
≥14
ICU admission 43% (37-43) ≥14 89% (85-92)
≥14
Death 40% (33-47) ≥14 80% (73-86)
≥14
17 Glampson et al.* (Jul 15, 2021) [Update to Apr 10 preprint]
UK Retrospective cohort
2 million adults >16 in Northwest London
Alpha^
Included BNT162b2 Documented infection
78% (73-82) 22-28 —
AZD1222 Documented infection
74% (65-81) 22-28
16 Andrejko et al.* (Jul 20, 2021) [update to May 25 preprint]
USA Test-negative case control
1023 California adults ≥18 years
B.1.427/ B.1.429 & Alpha^
Excluded BNT162b2 & mRNA-1273
Documented infection
66.9% (28.7--84.6%)
≥15 87.4% (77.2-93.1%)
≥15 ~14 weeks
Asymptomatic infection
— 68.3% (27.9-85.7%)
≥15
Symptomatic infection
— 91.3% (79.3-96.3)
≥15
Hospitalization — 100% ≥15
BNT162b2 Documented infection
— 87.0% (68.6-94.6)
≥15
mRNA-1273 Documented infection
— 86.2% (68.4-93.9)
≥15
15 Regev-Yochay et al.* ( July 7,2021) [Update to April 9 preprint]
Israel Prospective cohort
3578 HCWs in one Israeli health system
Alpha¶ Included BNT162b2 Asymptomatic infection
— 65% (45-79)
≥11
Asymptomatic infection presumed infectious (Ct< 30)
70% (43-84)
≥11
Symptomatic infection
90% (84-94)
≥11
Symptomatic infection presumed
88% (80-94)
≥11
14 | P a g e
infectious (CT<30)
14 Cabezas et al. (Apr 9, 2021)
Spain Prospective cohort
28,594 nursing home residents, 26,238 nursing home staff, and 61,951 healthcare workers in Catalan
original & Alpha¥¥ Excluded BNT162b2 HCWs cohort: infection
43% (37-47) 0-14 95% (93-96)
0
SNF staff cohort: infection
40% (33-47) 0-14 88% (85-90)
0
SNF resident cohort: infection
47% (42-51) 0-14 92% (91-93)
0
SNF resident cohort: hospitalization
55% (44-64) 0-14 97% (95-98)
0
SNF resident cohort: death
50%(37-60) 0-14 98% (97-99)
0
13 Bouton et al. (Mar 30, 2021)
USA – MA Prospective Cohort
10,950 healthcare workers in Boston
Original^ included BNT162b2 & mRNA-1273
Documented infection
82% (68-90) >14 days after dose 1 including some with dose 2 starting day 0
12 Thompson et al.* (Mar 29, 2021)
USA Prospective cohort
3,950 healthcare workers in eight US sites
Original¥ excluded BNT162b2 & mRNA1273
Documented infection
80% (59-90) ≥14 90% (68-97)
≥14
11 Shrotri et al.* (Jun 23, 2021) [Update to Mar 26 preprint]
UK Prospective cohort
10,412 care home residents aged ≥65 years from 310 LTCFs in England
Original and Alpha^
Stratified BNT162b2 Documented infection
65% (29-83) 35-48 —
AZD1222 Documented infection
68% (34-85) 35-48
10 Public Health England – March (Mar 17, 2021)
UK - England
Test Negative Case-Control
Adults in England over 70 years
Alpha^
? BNT162b2 Symptomatic infection
58% (49-65) ≥28 —
AZD1222 Symptomatic infection
58% (38-72) ≥35
Retrospective Cohort
Adults in England over 80 years
Included BNT162b2 Hospitalization1
42% (32-51) ≥14 —
Death1 54% (41-64) ≥14 AZD1222 Hospitalization
1 35% (4-56) 14-21
9 Yelin et al. (Mar 17, 2021)
Israel – Maccabi System
Retrospective Cohort
1.79 million enrollees, adults <90 years
Alpha^ excluded BNT162b2 Documented infection
91% (89-93) ≥35 days after dose 1 most with dose 2
Symptomatic infection
99% (95-99) ≥35 days after dose 1 most with dose 2
8 Britton et al.* (Mar 15, 2021)
USA – CT Retrospective Cohort
463 residents of two skilled nursing facilities
Original¥ stratified BNT162b2 Include Hx of COVID: Documented infection
63% (33-79) ≥14 days after dose 1 including some with dose 2 through day 7
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Purple text indicates new or updated study. Product Manufacturers: BNT162b2 (Pfizer), mRNA-1273 (Moderna), AZD1222 (Astra-Zeneca), Ad26.COV2.S (Janssen), Coronavac #Includes studies published/posted up through Wednesday of current week. Manuscripts with an asterisk (*) are peer-reviewed publications. 1VE for individuals with PCR confirmed symptomatic disease progressing to hospitalization or death 2VE for household members of vaccinated HCWs vs household members of unvaccinated HCWs ⴕReference group is not unvaccinated—uses vaccinated group before day 12 or day 14 after dose 1 as a reference group
experiencing outbreaks
Exclude Hx of COVID: Documented infection
60% (30-77) ≥14 days after dose 1 including some with dose 2 through day 7
7 Tande et al.* (Mar 11, 2021)
USA – Mayo Clinic
Retrospective Cohort
Asymptomatic screening of 39,156 patients: pre-surgical, pre-op PCR tests
original¥ included BNT162b2 & mRNA-1273
Asymptomatic infection
79% (63-88) >10 days after dose 1, including some with dose 2
80% (56-91)
>0
BNT162b2 Asymptomatic infection
79% (62-89) >10 80% (56-91)
>0
6 Azamgarhi et al. (Mar 9, 2021)
England--London
Retrospective cohort
2257 HCWs working at one hospital
Original and Alpha£
Included BNT162b2 Documented infection
80% (21-95) ≥14 —
5 Mousten-Helms et al. (Mar 9, 2021)
Denmark Retrospective Cohort
Long term care facilities in Denmark - 39,040 residents, 331,039 staff
original & Alpha¶¶ excluded BNT162b2 LTCF Resident: Documented Infection
21% (-11-44) >14 64% (14-84)
>7
LTCF Staff: Documented Infection
17% (4-28) >14 90% (82-95)
>7
4 Hyams et al.* (Jun 23, 2021) [Update to Mar 3 preprint]
UK – University of Bristol
Test Negative Case-Control
466 tests: >80 years hospitalized with respiratory symptoms
Alpha£ included BNT162b2 Hospitalization 79% (47-93) >14 —
AZD1222 Hospitalization 80% (36-95) >14
3 Dagan et al.* (Feb. 24, 2021)
Israel – Clalit Health System
Retrospective Cohort
596,618 – matched on demographics, residence, clinical characteristics
original & Alpha^ excluded BNT162b2 Documented infection
46% (40-51) 14-21 92% (88-95)
>7
Symptomatic infection
57% (50-63) 14-21 94% (87-98)
>7
Hospitalization 74% (56-86) 14-21 87% (55-100)
>7
Severe disease 62% (39-80) 14-21 92% (75-100)
>7
2 Public Health England – Feb. (Feb. 22, 2021)
UK - England
Screening Method
43,294 cases, with England as source population
Alpha^ included BNT162b2 Over 80 years: Symptomatic infection
57% (48-63) >28 88% (84-90)
7
1 Amit et al.* (Feb 18, 2021)
Israel Prospective Cohort
9,109 healthcare workers
original & Alpha¶ excluded BNT162b2 Documented infection
75% (72-84) ≥15 days after dose 1 including some with dose 2 through day 7
Symptomatic infection
85% (71-92) ≥15 days after dose 1 including some with dose 2 through day 7
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^Indicates predominant variant identified by study authors. If no ^ then variants identified through secondary source when possible. Please see additional footnotes. ¶The rise of SARS-CoV-2 variant Alpha in Israel intensifies the role of surveillance and vaccination in elderly | medRxiv ¥CDC Says More Virulent British Strain Of Coronavirus Now Dominant In U.S. : Coronavirus Updates : NPR £Coronavirus (COVID-19) Infection Survey, UK - Office for National Statistics ¶¶Denmark logs more contagious COVID variant in 45% of positive tests | Reuters ¥¥COVID variant first detected in UK now dominant strain in Spain ££Reporte-circulacion-variantes-al-9.04.21-PUBLICADO-FINAL.pdf (minsal.cl) ⴕⴕBased on https://outbreak.info/location-reports ψhttps://www.gov.uk/government/publications/covid-19-variants-genomically-confirmed-case-numbers/variants-distribution-of-cases-data
1.1 Inclusion criteria for VE studies Note: All VE studies now must meet these criteria to be in the VE table: • Published or preprint studies (not press release, presentations, media) • Needs confidence intervals around VE • Needs to include persons with & without infection or disease and with and without vaccination (ie a proper comparison group) • No case only studies (e.g., impact studies, risk of progression to severe disease (i.e. PHE). • No modeled comparison group • No comparison to historical cohort • VE should be adjusted or state adjustment made no difference • Outcomes must be lab confirmed, not syndromic • Documented vaccination status needed • VE for one vaccine or combined vaccines of same platform e.g. Pfizer + Moderna • No significant bias that likely affects results • Cannot include day 0-12 in unvaccinated definition • Cannot compare to early post vaccination to calculate VE (e.g. day 0-12 vs day 12-21) 1.2 VE Studies that do not meet criteria are listed below in case of interest:
1. Hunter P and Brainard J. Estimating the effectiveness of the Pfizer COVID-19 BNT162b2 vaccine after a single dose. A reanalysis of a study of 'real-world’ vaccination outcomes from Israel. medRxiv. Published online 2021:2021.02.01.21250957. doi: 10.1101/2021.02.01.21250957
2. Institut National de Santé Publique du Québec. Preliminary Data on Vaccine Effectiveness and Supplementary Opinion on the Strategy for Vaccination Against COVID-19 in Quebec in a Context of Shortage. Gouvernement du Québec. 2021:Publication No 3111. Available at: https://www.inspq.qc.ca/sites/default/files/publications/3111-vaccine-effectiveness-strategy-vaccination-shortage-covid19.pdf.
3. Weekes M, Jones NK, Rivett L, et al. Single-dose BNT162b2 vaccine protects against asymptomatic SARS-CoV-2 infection. Authorea. Published online Feb 24, 2021. doi: 10.22541/au.161420511.12987747/v1
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4. Aran D. Estimating real-world COVID-19 vaccine effectiveness in Israel using aggregated counts. Published online Mar 4, 2021. Available at: https://github.com/dviraran/covid_analyses/blob/master/Aran_letter.pdf.
5. Shah ASV, Gribben C, Bishop J, et al. Effect of vaccination on transmission of COVID-19: an observational study in healthcare workers and their households. medRxiv. Published online 2021:2021.03.11.21253275. doi: 10.1101/2021.03.11.21253275
6. Monge S, Olmedo C, Alejos B, et al. Direct and indirect effectiveness of mRNA vaccination against SARS-CoV-2 infection in long-term care facilities in Spain. medRxiv. Published online 2021:2021.04.08.21255055 doi: 10.1101/2021.04.08.21255055
7. Vahidy FS, Pischel L, Tano ME, et al. Real World Effectiveness of COVID-19 mRNA Vaccines against Hospitalizations and Deaths in the United States. medRxiv. Published online 2021:2021.04.21.21255873 doi: 10.1101/2021.04.21.21255873
8. Swift MD, Breeher LE, Tande AJ, et al. Effectiveness of Messenger RNA Coronavirus Disease 2019 (COVID-19) Vaccines Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in a Cohort of Healthcare Personnel. Clin Inf Dis. Published online Apr 26, 2021:2021;ciab361. doi: 10.1093/cid/ciab361
9. Zaqout A, Daghfal J, Alaqad I, et al. The initial impact of a national BNT162b2 mRNA COVID-19 vaccine rollout. medRxiv. Published online 2021:2021.04.26.21256087 doi: 10.1101/2021.04.26.21256087
10. Cavanaugh AM, Fortier S, Lewis P, et al. COVID-19 Outbreak Associated with a SARS-CoV-2 R.1 Lineage Variant in a Skilled Nursing Facility After Vaccination Program – Kentucky, March 2021. MMWR Morb Mortal Wkly Rep. 2021;70:639-643. doi: 10.15585/mmwr.mm7017e2
11. Tang L, Hijano DR, Gaur AH, et al. Asymptomatic and Symptomatic SARS-CoV-2 Infections After BNT162b2 Vaccination in a Routinely Screened Workforce. JAMA. Published online May 6, 2021:2021;325(24):2500-2502. doi: 10.1001/jama.2021.6564
12. Chodick G, Tene L, Rotem Ran S, et al. The Effectiveness of the Two-Dose BNT162b2 Vaccine: Analysis of Real-World Data. Clin Infect Dis. Published online May 17, 2021:2021;ciab438. doi: 10.1093/cid/ciab438
13. Lopez Bernal J, Andrews N, Gower C, et al. Effectiveness of BNT162b2 mRNA vaccine and ChAdOx1 adenovirus vector vaccine on mortality following COVID-19. medRxiv. Published online 2021:2021.05.14.21257600 doi: 10.1101/2021.05.14.21257218
14. Bianchi FB, Germinario CA, Migliore G, et al. BNT162b2 mRNA COVID-19 Vaccine Effectiveness in the Prevention of SARS-CoV-2 Infection: A Preliminary Report. J Infect Dis. Published online May 19, 2021:2021;jiab262. doi: 10.1093/infdis/jiab262
15. Walsh J, Skally M, Traynor L, et al. Impact of first dose of BNT162b2 vaccine on COVID-19 infection among healthcare workers in an Irish hospital. Ir J Med Sci. Published online May 2021:1-2. doi:10.1007/s11845-021-02658-4
16. Yassi A, Grant JM, Lockhart K, et al. Infection control, occupational and public health measures including mRNA-based vaccination against SARS-CoV-2 infections to protect healthcare workers from variants of concern: a 14-month observational study using surveillance data. medRxiv. Published online 2021:2021.05.25.21257600. doi:10.1101/2021.05.21.21257600
17. Kumar S, Saxena S, Atri M, Chamola SK. Effectiveness of the Covid-19 vaccine in preventing infection in dental practitioners: results of a cross-sectional questionnaire based survey. medRxiv. Published online 2021:2021.05.28.21257967. doi:10.1101/2021.05.28.21257967
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18. Shrestha NK, Nowacki AS, Burke PC, Terpeluk P, Gordon SM. Effectiveness of mRNA COVID-19 Vaccines among Employees in an American Healthcare System. medRxiv. Published online 2021:2021.06.02.21258231. doi:10.1101/2021.06.02.21258231
19. Riley S, Wang H, Eales O, et al. REACT-1 Round 12 Report: Resurgence of SARS-CoV-2 Infections in England Associated with Increased Frequency of the Delta Variant.; 2021. https://spiral.imperial.ac.uk/bitstream/10044/1/89629/2/react1_r12_preprint.pdf
20. Ben-Dov IZ, Oster Y, Tzukert K, et al. The 5-months impact of tozinameran (BNT162b2) mRNA vaccine on kidney transplant and chronic dialysis patients. medRxiv. Published online June 16, 2021:2021.06.12.21258813. doi:10.1101/2021.06.12.21258813
21. Victor PJ, Mathews KP, Paul H, Murugesan M, Mammen JJ. Protective Effect of COVID-19 Vaccine Among Health Care Workers During the Second Wave of the Pandemic in India. Mayo Clin Proc. Published online 2021.
22. Chodick G, Tene L, Patalon T, et al. Assessment of Effectiveness of 1 Dose of BNT162b2 Vaccine for SARS-CoV-2 Infection 13 to 24 Days After Immunization. JAMA Netw Open. Published online Jun 7, 2021:2021;4(6):e2115985. doi: 10.1001/jamanetworkopen.2021.15985
23. Bahl A, Johnson S, Maine G, et al. Vaccination reduces need for emergency care in breakthrough COVID-19 infections: A multicenter cohort study. medRxiv. Published online 2021:2021.06.09.21258617. doi:10.1101/2021.06.09.21258617
24. Zacay G, Shasha D, Bareket R, et al. BNT162b2 Vaccine Effectiveness in Preventing Asymptomatic Infection with SARS-CoV-2 Virus: A Nationwide Historical Cohort Study. Open Forum Infect Dis. Published online June 9, 2021:2021;8(6). doi: 10.1093/ofid/ofab262
25. Ross C, Spector O, Tsadok MA, Weiss Y, Barnea R. BNT162b2 mRNA vaccinations in Israel: understanding the impact and improving the vaccination policies by redefining the immunized population. medRxiv. Published online 2021:2021.06.08.21258471. doi:10.1101/2021.06.08.21258471
26. Malinis M, Cohen E, Azar MM. Effectiveness of SARS-CoV-2 vaccination in fully-vaccinated solid organ transplant recipients. Am J Transplant. Published online June 2021. doi:10.1111/ajt.16713
27. Ramakrishnan, M., & Subbarayan, P. Impact of vaccination in reducing Hospital expenses, Mortality and Average length of stay among COVID 19 patients. A retrospective cohort study from India. medRxiv, Published online 2021: 2021.06.18.21258798. doi:10.1101/2021.06.18.21258798
28. Sansone E, Sala E, Tiraboschi M, et al. Effectiveness of BNT162b2 vaccine against SARS-CoV-2 among healthcare workers. Med Lav. Published online 15 June 2021. doi: 10.23749/mdl.v112i3.11747.
29. Jaiswal A, Subbaraj V, Wesley J, et al. COVID-19 vaccine effectiveness in preventing deaths among high-risk groups in Tamil Nadu, India. Indian J Med Res. Accessed online ahead of print 23 June 2021. doi: 10.4103/ijmr.ijmr_1671_21.
30. Harris RJ, Hall JA, Zaidi A, et al. Effect of Vaccination on Household Transmission of SARS-CoV-2 in England. N Engl J Med. Published online Jun 23, 2021. doi: 10.1056/NEJMc2107717
31. Hitchings MDT, Ranzani OT, Torres MSS et al. Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study. medRxiv, Published online 2021: 2021.04.07.21255081 .21258798. doi:10.1101/2021.04.07.21255081
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32. Knobel P, Serra C, Grau S, et al. COVID-19 mRNA vaccine effectiveness in asymptomatic healthcare workers [published online ahead of print, 2021 Jun 24]. Infect Control Hosp Epidemiol. 2021;1-7. doi:10.1017/ice.2021.287
33. Kale P, Bihari C, Patel N, et al. Clinicogenomic analysis of breakthrough infections by SARS CoV2 variants after ChAdOx1 nCoV-19 vaccination in healthcare workers. medRxiv, Published online 2021:2021.06.28.21259546. doi: 10.1101/2021.06.28.21259546
34. Gazit S, Mizrahi B, Kalkstein N, et al. BNT162b2 mRNA Vaccine Effectiveness Given Confirmed Exposure; Analysis of Household Members of COVID-19 Patients. medRxiv, published online 2021.06.29.21259579. doi:10.1101/2021.06.29.21259579
35. Paris C, Perrin S, Hamonic S, et al. Effectivness of mRNA-BNT162b2, mRNA-1273, and ChAdOx1 nCoV-19 vaccines against COVID-19 in health care workers: an observational study using surveillance data. Clin Microbiol Infect. Published online Jun 29, 2021. doi: 10.1016/j.cmi.2021.06.043
36. Kojima N, Roshani A, Brobeck M, et al. Incidence of Severe Acute Respiratory Syndrome Coronavirus-2 infection among previously infected or vaccinated employees. medRxiv, Published online 2021:2021.07.03.21259976. doi: 10.1101/2021.07.03.21259976
37. Lumley SF, Rodger G, Constantinides B, et al. An observational cohort study on the incidence of SARS-CoV-2 infection and B.1.1.7 variant infection in healthcare workers by antibody and vaccination status. Clin Inf Dis. Published online Jul 12, 2021:2021;ciab608. doi: 10.1093/cid/ciab608
38. Rovida F, Cassaniti I, Paolucci S, et al. SARS-CoV-2 vaccine breakthrough infections are asymptomatic or mildly symptomatic and are infrequently transmitted. medRxiv, Published online 2021.06.29.21259500. doi:10.1101/2021.06.29.21259500
39. Williams C, Al-Bargash D, Macalintal C, et al. COVID-19 Outbreak Associated with a SARS-CoV-2 P.1 Lineage in a Long-Term Care Home after Implementation of a Vaccination Program – Ontario, April-May 2021. Clin Inf Dis. Published online Jul 8, 2021:2021;ciab617. doi: 10.1093/cid/ciab617
40. Bailly B, Guilpain L, Bouiller K, et al. BNT162b2 mRNA vaccination did not prevent an outbreak of SARS COV-2 variant 501Y.V2 in an elderly nursing home but reduced transmission and disease severity [published online ahead of print, 2021 May 16]. Clin Infect Dis. 2021;ciab446. doi:10.1093/cid/ciab446
41. Charmet T, Schaeffer L, Grant R, et al. Impact of original, B.1.1.7, and B.1.351/P.1 SARS-CoV-2 lineages on vaccine effectiveness of two doses of COVID-19 mRNA vaccines: Results from a nationwide case-control study in France [published online ahead of print, 2021 Jul 13]. Lancet Regional Health—Eur. 2021;8:100171. doi: 10.1016/j.lanepe.2021.100171
42. Bermingham CR, Morgan J, Ayoubkhani D, et al. Estimating the effectiveness of the first dose of COVID-19 vaccine against mortality in England: a quasi-experimental study. medRxiv, Published online 2021.07.12.21260385. doi:10.1101/2021.07.12.21260385
43. Waldman SE, Adams JY, Albertson TE, et al. Real-world impact of vaccination on COVID-19 incidence in health care personnel at an academic medical center. Infect Control Hosp Epidemiol. Published online Jul 21, 2021:2021;1-21. doi: 10.1017/ice.2021.336
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2. Summary of Study Results for Post-Authorization COVID-19 Vaccine Effectiveness Against Transmission* # Reference
(date) Country Design Population Dominant
Variants (Alpha=B.1.1.7 Beta=B.1351 Gamma=P.1 Delta=B.1617.2
History of COVID
Vaccine Product
Outcome Measure
1st Dose VE (95%CI)
Days post 1st dose 2nd Dose VE (95% CI) Days post 2nd dose
Max Duration of follow up after fully vaccinated
5 Layan, Gilboa et al (July 16,2021)
Israel Prospective cohort
215 index cases and 687 household contacts from 210 Israeli households
Original and Alpha¶
Included BNT162b2 Transmission to HHC by vaccinated vs. unvaccinated cases
— 78(30-94) 7+ ~12 weeks
4 Prunas et al (July 16, 2021)
Israel Retrospective cohort
253,564 Israeli individuals from 65,264 households with at least 1 infected individual and at least 2 members
Original and Alpha¶
Unknown BNT162b2 Infectiousness given Infection
— — 41.3(9.5-73.0) 10+
Transmission 88.5(82.3-94.8)
3 Harris et al* (June 23, 2021) [Update to Apr 28 preprint]
UK Retrospective cohort, case-control
970,128 household contacts of index case (unvaccinated, vaccinated with AZD1222 or BNT162b)
Alpha£ Unknown AZD1222 Documented infection
48(38-57)
>21 days after dose 1, including some with dose 2
—
BNT162b2 46(38-53
2 Salo et al (July 10, 2021) [Update to May 30 preprint]
Finland Retrospective cohort
HCW and their unvaccinated spouses
Alphaⴕⴕ Excluded BNT162b2 & mRNA-1273
Documented infection in HCW’s unvaccinated spouses
8.7 (-28.9-35.4)
2 weeks — *10 weeks since dose 1
Documented infection in HCW’s unvaccinated spouses
42.9 (22.3-58.1)
10 weeks (combo of 1+2 dose recipients)
—
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1 Shah et al. (Mar 11, 2021)
UK - Scotland
Retrospective Cohort
144,525 healthcare workers (HCWs) and 194,362 household members
original &
Alpha£
excluded BNT162b2 & AZD1222
Household members of HCWs: Documented infection2
30% (22-37)
≥14 54% (30-70) ≥14
*Study results captured during literature search of vaccine effectiveness studies. Note this is not an exhaustive list of transmission studies.
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3. Vaccine Impact: Summary of Ecologic Study Results for Post-Authorization COVID-19 Vaccine Products#
# Reference (date) Country Design Population Dominant Variants
Vaccine Product Descriptive Findings
36 Waldman et al* (July 21, 2021)
USA Retrospective cohort
16,156 faculty, students, and staff at an academic medical center
Original and Alpha ⴕⴕ
BNT162b2 and mRNA-1273
This retrospective cohort study assessed the impact of vaccination on the incidence of SARS-CoV-2 infection, hospitalization, and mortality among faculty, students, and staff at the University of California Davis medical center. COVID-19 incidence decreased from 3.2% during the 8 weeks before vaccination began to 0.38% 4 weeks after the start of vaccination. A single dose of either vaccine reduced the hazard of testing positive by 48% (HR=0.52, CI 0.40-0.68) and the positivity rate for SARS-CoV-2 14+ days after the second dose was 0.04%. There were no hospitalizations or deaths among fully vaccinated (14+ days after dose 2) HCWs who tested positive.
35 Toniassoa et al (July 13,2021)
Brazil Cross-sectional
7523 HCWs in a hospital in Southern Brazil
Unknown CoronaVac, AZD1222
This is a cross-sectional study conducted on 7523 vaccinated( both partial and full vaccination) Brazilian healthcare workers to detect the prevalence of COVID-19 diagnosis The diagnosis of COVID-19 in the past reduced the prevalence of new infections by 68% (PR: 0.32 95% CI: 0.19 – 0.56). After the first dose, infection prevalence decreased by 7% every week (PR: 0.93 95% CI: 0.89 – 0.97) regardless of the type of vaccine. An important finding was that a previous diagnosis of COVID-19 over 45 days ago reduced prevalence by 71% (PR: 0.29 95% CI: 0.11 – 0.75) among those professionals.
34 Wiliams et al (July 8,2021)
USA Outbreak study
31 residents and 22 staff members working in a LTCF in the US
Gamma BNT162b2 and mRNA-1273
This study was conducted in an outbreak setting in a long-tern care facility where the predominant SARS-CoV-2 variant was determined as the P.1(Gamma variant).Vaccine effectiveness against SARS-CoV-2 infection was 52.5% (95%CI 26.9-69.1%) in residents and 66.2% (95%CI, 2.3-88.3%) in staff. VE against severe illness was 78.6% (95%CI 47.9-91.2) in residents. Assuming that all residents and staff of the home were exposed, the estimated VE against SARS-CoV-2 infection was 66.0% (95%CI 40.6-80.5%) in residents and 63.5% (95%CI 11.5-85.0%) in staff
33 Shacham et al (July 5, 2021)
USA Ecologic Residents of 115 counties and 2 cities in Missouri
Unknown Unspecified (BNT162b2, mRNA-1273, Ad26.COV2.S available)
Ecologic study evaluating the relationship between the cumulative proportion of residents vaccinated and weekly incidence of COVID-19 by location in 115 counties and 2 cities in Missouri (total n=117 locations) from January 4 to June 26, 2021 (25 weeks). The relationship was found to likely be linear during the study period and was adjusted for other variables related to COVID-19 (population, proportion of nonwhite residents, median household income, proportion of residents in public-facing occupations). The final adjusted
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linear model showed the relationship was significant, with every percent increase in population vaccinated resulting in 3 fewer weekly COVID-19 cases (β -3.74, p<0.001). Locations with higher proportions of nonwhite residents were also likely to experience lower weekly incidence of COVID-19 after adjusted for other variables (β -1.48, p=0.037).
32 Greene, Sharon et al (July 5,2021)
USA Regression discontinuity
1,101,467 65-84-year-old NYC residents
Unknown BNT162b2 and mRNA-1273
A regression discontinuity study comparing the rate of hospitalization and deaths among 65-84 year-old during an 8-week post-implementation phase of SARS-CoV-2 vaccines in New York City with the pre-implementation period, controlling for the epidemic trend among 45-64-year-olds, a group without concurrent age-based vaccine eligibility. It is observed that hospitalization rates among 65-84 year-olds during the post-implementation period had a statistically significant decrease as compared to the pre-implementation period with a RR of 0.85(95% CI 0.74-0.97). Similar decrease in death rates was observed during the post-implementation period but this finding was not statistically significant (RR 0.85, 95% CI: 0.66–1.10, P = 0.22).
31 Victora et al (June 19,2021)
Brazil Ecologic Brazilian population Gamma AZD1222 and CoronaVac
Calculated proportionate mortality of COVID-19 deaths at ages 70-79 and 80+ and COVID-19 age-specific mortality rates using Brazilian Ministry of Health data from January 3- May 15, 2021 in a setting of predominant Gamma variant transmission. The proportion of all COVID-19 deaths for ages 80+ years in weeks 1-6 was 25% which subsequently reduced to 12.4% in week 19 following the vaccination program. For individuals aged 70-79 years, the proportionate mortality showed a substantial decline in April-May. The mortality rate for persons aged 80+ reduced from 13.3 in January to 8.0 in week 19, and a gradual decline in the rate ratios was observed for ages 70-79 from 13.8 in week 1 to 5.0 in week 19.
30 Jacobson et al (June 17,2021)
USA Retrospective cohort
Healthcare workers Alpha, Epsilon
BNT162b2 and mRNA-1273
A retrospective report of 660 SARS-Cov-2 cases detected by PCR test among HCW at a single-site medical center. Described proportions of cases and compared mutation prevalence among unvaccinated, early post-vaccinated (≤14 days after dose 1), partially vaccinated (>14 days after dose 1 and ≤14 days after dose 2), and fully vaccinated (>14 days after dose 2). 189 of 660 cases detected were post-vaccine SARS-CoV-2 cases (PVSC, defined as occurring in those who had received at least one dose of vaccine). 60.3% of the 189 PVSCs occurred early post-vaccination, 25.9% were among partially vaccinated individuals, and 13.8% were among those fully vaccinated. Incidence of the L452R mutation (presumed to indicate the Epsilon variant) did not vary by vaccination status.
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29 Christie et al (June 7, 2021)
USA Impact US population Unknown Unspecified ( BNT162b2, mRNA-1273
Calculated rates of COVID-19 cases, emergency department (ED) visits, hospital admissions, and deaths by age group during November 29–December 12, 2020 (pre-vaccine) and April 18–May 1, 2021. The rate ratios comparing the oldest age groups (≥70 years for hospital admissions; ≥65 years for other measures) with adults aged 18–49 years were 40%, 59%, 65%, and 66% lower, respectively, in the latter period
28 Guijarro et al (June 28, 2021) [Update to Jun 3 preprint]
Spain Impact HCW compared to community
Unknown BNT162b2 Incidence rates of SARS-CoV-2 infection after the first dose of mRNA SARS-CoV-2 vaccine declined by 71% (Incidence Rate Ratio (IRR) 0.286 , 95% confidence interval (CI) 0.174-0.468) and by 97% (IRR 0.03 95% CI 0.013-0.068,) after the second dose as compared to the perivaccine time. SARS-CoV-2 incidence rates in the community (with a negligible vaccination rate) had a much lower decline: 2% (IRR 0.984; 95% CI 0.943-1.028) and 61% (IRR 0.390, 95% CI 0.375-0.406) for equivalent periods. Adjusting for the decline in the community, the reduction in the incident rates among HCW were 73% (IRR 0.272; 95% CI 0.164-0.451) after the first dose of the vaccine and 92 % (IRR 0.176, 95% CI 0.033-0.174;) after the second dose.
27 Sansone et al (May 13, 2021)
Italy Impact HCW Alpha BNT162b2 Community cases increased during the study period while cases in vaccinated HCWs only minimally increased and then stabilized.
26 White et al. (May 19, 2021)
USA Impact LTCF Unknown BNT162b2 and mRNA-1273
Evaluated an administrative database of a large LTCF company across USA. Evaluated 21,815 persons, . 80% Pfizer+20% Moderna; 60% 2 dose +24% 1 dose. Disease incidence goes down in vaccinated/unvaccinated.
25 Munitz et al (May 18, 2021)
Israel Ecologic Israeli Population Alpha BNT162b2 Evaluated the transmission dynamics of B.1.1.7(Alpha) variant and to study the impact of the national vaccination program on the general population and the elderly. The study analysed 292,268 RT-PCR samples collected from December 6,2020 to February 10,2021. In the first week of February, B.1.1.7 variant was the predominant variant identified in more than 90% of the positive tests. The B.1.1.7 variant was 1.45 more transmissible than the wild-type strain (95% confidence interval [CI]: 1.20–1.60). The effective reproduction number for B.1.1.7 was estimated to be 1.71 (95% CI: 1.59– 1.85) compared with 1.12 (95% CI: 1.10–1.15) observed for the wild-type. To evaluate the impact of preventive policies against the B.1.1.7 variant, the authors stratified the distribution of new COVID-19 cases in different age groups. It was observed that an increase in the incidence of the variant was noted in the 60+ years aged group through January 13,2021, following which the incidence plateaued and subsequently declined, which coincided with the rapid uptake of vaccine in this age group.
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24 Domi et al (May 6,2021)
USA Impact LTCF unknown BNT162b2 Evaluated data from 2501 nursing homes in the US in 17 states. Used zero-inflated negative binomial mixed effects regressions to model the associations of time since the vaccine clinic ending the week of December 27, 2020 (cohort 1), January 3, 2021 (cohort 2) or January 10, 2021 (cohort 3) controlling for county rate of COVID-19, bed size, urban location, racial and ethnic census, and level of registered nurses with resident cases and deaths of COVID-19 and staff cases of COVID-19. Resident and staff cases trended downward in all three cohorts following the vaccine clinics. Time following the first clinic at five and six weeks was consistently associated with fewer resident cases (IRR: 0.68 [95% CI: 0.54-0.84], IRR: 0.64 [95% CI: 0.48-0.86], respectively); resident deaths (IRR: 0.59 [95% CI: 0.45-0.77], IRR: 0.45 [95% CI: 0.31-0.65], respectively); and staff cases (IRR: 0.64 [95% CI: 0.56-0.73], IRR: 0.51 [95% CI: 0.42-0.62], respectively). Other factors associated with fewer resident and staff cases included facilities with less than 50 certified beds and high nurse staffing per resident day (>0.987). Contrary to prior research, higher Hispanic non-white resident census was associated with fewer resident cases (IRR: 0.42, 95% CI: 0.31-0.56) and deaths (IRR: 0.18, 95% CI: 0.12-0.27).
23 Haas et al. (May 13, 2021)
Israel Impact Israeli population Alpha¶ BNT162b2 Used national surveillance data from the first 112 days (Dec 20, 2020 ‒ Apr 10, 2021) of Israel’s vaccination campaign to estimate averted burden of four outcomes: SARS-CoV-2 infections and COVID-19-related hospitalizations, severe or critical hospitalizations, and deaths. Estimated that Israel’s vaccination campaign averted 158,665 (95% CI: 115,899‒201,431) SARS-CoV-2 infections, 24,597 (6,622‒42,571) hospitalizations, 17,432 (3,065‒31,799) severe and critical hospitalizations, and 5,533 (-1,146‒12,213) deaths. Of these, 66% of hospitalizations and 91% of deaths averted were among those ≥65 years of age. 73% of SARS-CoV-2 infections and 79% of COVID-19-related hospitalizations and deaths averted stemmed from the protective effects in fully vaccinated persons.
22 Rana et al. (May 11, 2021)
Bangladesh Cross-sectional
11 districts in Bangladesh Unknown AZD1222 Cross-sectional study in 11 districts in Bangladesh. Offered voluntary testing. A total of 6146 suspected samples were tested and 1752 were found positive for SARS-CoV-2. Of the positives, 200 individuals had received a first dose of AZ. Among the vaccinated cases, 165 (82.5%) did not require hospitalization and 177 (88.5%) did not have respiratory difficulties.
21 Garvey et al.* (Apr 28, 2021)
UK ecologic University Hospitals Birmingham (UHB) HCWs
Alpha£ BNT162b2 An occupational health database of all COVID-19 positive HCWs was interrogated against an informatics search of all vaccinated HCWs. A multivariate logistic regression model
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found that being vaccinated was associated with a decreased probability of testing positive (p = 1.40 × 10−10, odds ratio 2.35, 95% CI: 1.81-3.05). The model also found that the probability of testing positive decreases as the gap between vaccination and testing increases (p = 0.00607). A weighted cox regression demonstrated that vaccination was associated with a significantly lower hazard of testing positive during the time period in question (p < 0.0001). This model gave a generalized concordance probability of 0.24 (95% CI: 0.20, 0.28), meaning that a HCW who had been vaccinated had only a 24% probability of testing positive before an equivalent unvaccinated HCW.
20
Ackland et al. (Apr 22, 2021)
UK ecologic UK adults Alpha^ BNT162b2, mRNA-1273, AZD1222
Used national data on cases and deaths to estimate CFR. Found that from the second half of January, the CFRs for older age groups show a marked decline. Since the fraction of the VOC has not decreased, this decline is likely to be the result of the rollout of vaccination.
19 Lillie et al.* (Apr 24, 2021)
UK ecologic Healthcare workers Alpha^ BNT162b2 Symptomatic staff underwent routine testing together with routine (asymptomatic) Lateral Flow Device (LFD) testing of all clinical staff. Starting Jan 2021 827 (8.3%) of staff had received their first dose of vaccine, increasing to 8243 (82.5%) by the end of February. Cases of SARS-CoV-2 amongst staff reduced from 120 cases to 10 cases over the same period.
18 Rossman et al.* (Apr 19, 2021) Update to Feb 9 preprint)
Israel Impact Israeli population Alpha^ BNT162b2 Analysis of data from the Israeli Ministry of Health collected between 28 August 2020 and 24 February 2021. Compared: (1) individuals aged 60 years and older prioritized to receive the vaccine first versus younger age groups; (2) the January lockdown versus the September lockdown; and (3) early-vaccinated versus late-vaccinated cities. A larger and earlier decrease in COVID-19 cases and hospitalization was observed in individuals older than 60 years, followed by younger age groups, by the order of vaccination prioritization. This pattern was not observed in the previous lockdown and was more pronounced in early-vaccinated cities.
17 Mor et al. (Apr 16, 2021)
USA Impact 80 nursing homes located across 21 states.
unknown BNT162b2 & mRNA-1273
Matched pairs analysis of 280 nursing homes in 21 states owned and operated by the largest long-term care provider in the United States. Compared data from nursing homes that had their initial vaccine clinics between December 18, 2020 and January 2, 2021, versus between January 3, 2021 and January 18, 2021. Outcomes were incident SARS-CoV-2 infections per 100 at-risk residents per week and hospital transfers and/or deaths per 100 residents with confirmed SARS-CoV-2 infection per day, averaged over a week. Adjusted for facility infection rates in the fall. After 1 week,
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early vaccinated facilities had a predicted 2.5 fewer incident SARS-CoV-2 infections per 100 at-risk residents per week (95% CI: 1.2–4.0).
16 Faria et al. (Apr 15, 2021)
Brazil Impact (model)
HCWs in Sao Paulo Gamma^ CoronaVac HCWs in Hospital das Clinicas received vaccine before the general population of Sao Paulo. Using a period before vaccination, a Poisson regression was fit to model expected COVID-19 cases among HCWs based on the number of cases in Sao Paulo. Study then compared the expected number of cases among HCWs after vaccination (based on the model) to the observed numbers of cases in HCWs. The estimated effectiveness 2 and 3 weeks after the 2nd dose was 50.7% and 51.8%, respectively, and increased over the next 2 weeks.
15 PHE (Apr 8, 2021)
UK Impact UK adults Alpha^ BNT162b2 & mRNA-1273
Daily impact of vaccination on deaths was estimated based on vaccine effectiveness against mortality multiplied by vaccine coverage. Observed deaths were then divided by the impact to estimate the expected deaths in the absence of vaccination. By the end of March 2021, they estimated that 9,100 deaths were averted in individuals aged 80 years and older, 1,200 in individuals aged 70 to 79, and 100 in individuals aged 60 to 69 years giving a total of 10,400 deaths averted in individuals aged 60 years or older.
14 Jones et al. (Apr 8, 2021)
UK Ecologic Cambridge University healthcare workers
Alpha^ BNT162b2 Screened vaccinated and unvaccinated HCWs for two weeks then compared proportion of positive tests in unvaccinated vs. vaccinated groups. Found four-fold decrease in risk of asymptomatic SARS-Cov-2 infection among HCWs ≥12 days post-vaccination compared to unvaccinated HCWs.
13 Rivkees et al. (Apr 7, 2021)
US - FL Ecologic Florida population original and Alpha¥
BNT162b2 & mRNA-1273
Ecologic analysis of vaccinations in Florida. Through March 15, 2021, 4,338,099 individuals received COVID-19 vaccine, including 2,431,540 individuals who completed their vaccination series. Of all those vaccinated, 70% were 65 years of age and older, and 63% of those 65 years of age and older. Beginning February 1, 2021, the decline in the number of new cases per week became greater in those 65 years of age and older than those younger. By March 15, 2021, the number of new cases, hospitalizations, and deaths per day for those 65 years of age and older relative to mid-January, were 82%, 80%, and 92% lower respectively. In comparison, the number of new cases, hospitalizations, and deaths per day for those younger than 65 years of age were 70%, 60%, and 87% lower respectively. Reductions in rates in those 65 year of age and older, were thus greater than in those who were younger (p-value <0.01, Wilcoxon test).
12 Hollinghurst et al. (Mar 24, 2021)
UK—Wales Cohort (but no control)
14,501 vaccinated older adult residents in a Wales care home
original and Alpha£
BNT162b2 & AZD1222
Observational data-linkage using electronic health records and administrative data. Developed a Cox proportional
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hazards models to estimate hazard ratios for the risk of testing positive for SARS-CoV-2 infection following vaccination. Outcome of interest was the time to a positive SARS-CoV-2 PCR test following vaccination. Kaplan-Meier curve and empirical cumulative distribution function suggest a susceptible period of vaccinated individuals up to 42 days, with approximately 40% of individuals having a positive PCR test within 7 days, 60% within 14-days, 85% within 21-days, 90% within 28-days, and over 95% within 35-days.
11 Milman et al. (Jun 11, 2021) [Update to Mar 23 preprint]
Israel Ecologic Maccabi Healthcare Services, 644,609 individuals in 177 communities
original & Alpha¶
BNT162b2 Rates of vaccination in each community are highly correlated with a later decline in infections among a cohort of under 16 years old which are unvaccinated. These results provide observational evidence that vaccination not only protects individual vaccinees but also provides cross-protection to unvaccinated individuals in the community.
10 Keehner et al. (Mar 23, 2021)
US - CA Ecologic Healthcare workers in the UCLA and UCSD systems
original¥ BNT162b2 & mRNA-1273
Among the vaccinated health care workers, 379 people tested positive for SARS-CoV-2 at least 1 day after vaccination, and the majority (71%) of these persons tested positive within the first 2 weeks after the first dose.
9 Daniel et al. (Mar 23, 2021)
US - TX Ecologic Healthcare workers from the UTSW
original¥ BNT162b2 & mRNA-1273
After vaccination, they observed a greater than 90% decrease in the number of employees who are either in isolation or quarantine.
8 Benenson et al. (Mar 23, 2021)
Israel Ecologic Healthcare workers at Hadassah Hebrew University Medical Center
Alpha^ BNT162b2 Among vaccinated workers, the weekly incidence of COVID-19 since the first dose declined notably after the second week; the incidence of infection continued to decrease dramatically and then remained low after the fourth week.
7 Roghani (Mar 17, 2021)
US – TN Ecologic Residents of Tennessee original¥ BNT162b2 & mRNA-1273
Between 12/17/20 and 3/3/21 found that the daily incidence among the entire population over 71 dropped from 0.1% to 0.01% of the age group (90% reduction) while for younger ages incidence dropped from 0.2% to 0.05% (75% reduction).
6 Puranik et al. (March 8, 2021)
US Ecologic 87 million individuals from 580 counties in the United States
original¥ BNT162b2 & mRNA-1273
Compares the cumulative county-level vaccination rates with the corresponding COVID-19 incidence rates among 87 million individuals from 580 counties in the United States, including 12 million individuals who have received at least one vaccine dose. Found that cumulative county-level vaccination rate through March 1, 2021 is significantly associated with a concomitant decline in COVID-19, with stronger negative correlations in the Midwestern counties and Southern counties.
5 Rinott et al (March 8, 2021)
Israel Ecologic Persons needing ventilation
Orginal & alpha
BNT162b2 number of COVID-19 patients aged ≥70 years (who had the highest 2-dose vaccination coverage, 84.3%) requiring mechanical ventilation was compared with that of patients aged <50 years, who had the lowest 2-dose vaccination
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#Includes studies published/posted up through Wednesday of current week. ^Indicates predominant variant identified by study authors. If no ^ then variants identified through secondary source when possible. Please see additional footnotes. ¶The rise of SARS-CoV-2 variant Alpha in Israel intensifies the role of surveillance and vaccination in elderly | medRxiv
¥CDC Says More Virulent British Strain Of Coronavirus Now Dominant In U.S. : Coronavirus Updates : NPR £Coronavirus (COVID-19) Infection Survey, UK - Office for National Statistics ⴕⴕBased on https://outbreak.info/location-reports
Please direct any questions about content to: • Anurima Baidya ([email protected]) • Karoline Walter ([email protected])
coverage (9.9%). Since implementa- tion of the second dose of the vaccination campaign, the ratio of COVID-19 patients requiring mechanical ventilation aged ≥70 years to those aged <50 years has declined 67%, from 5.8:1 during October–December 2020 to 1.9:1 in February 2021.
4 De-Leon et al. (Feb 8, 2021)
Israel Ecologic Modeling
Israel population over 60 years old
original & Alpha¶
BNT162b2 Looked at whether the high vaccine coverage among individuals aged over 60 years old creates an observable change in disease dynamics using real and simulated data. Based on model, vaccine is at least 50% effective.
3 CHPE-LTC (Feb 10, 2021)
US - national Ecologic Residents of long term care facilities that received vaccine through the federal pharmacy partnership.
original¥ BNT162b2 & mRNA-1273
Three weeks after the first vaccine clinic the rates of new COVID-19 infection dropped more in the 797 SNFs that held vaccine clinic compared to those that did not in the same county (48% vs 21%, respectively).
2 Dunbar et al. (Feb 10, 2021)
US - VA Ecologic Healthcare workers in an academic hospital
original¥ BNT162b2 & mRNA-1273
After 60% of employees received the 1st vaccine dose, the HCW COVID-19 infection rate decreased by 50%. HCWs who were 14-28 days and > 28 days post-first vaccine dose were less likely COVID-19 infected than non-vaccine recipients.
1 Domi et al. (Feb 4, 2021)
US Ecologic LTCF residents and staff original¥ BNT162b2 & mRNA-1273
Used CMS NHSN Public File data and Tiberius data and created an analytic cohort based on the schedule of the vaccination clinics taking place during the first week of the program (12/18/20 to 12/27/20). Created a comparison group, composed of facilities located in the same county that did not have a first vaccination clinic during that period. Found that COVID-19 cases decreased at a faster rate among both residents and staff associated with nursing homes that had completed their first clinic. Vaccinated nursing homes experienced a 48% decline in new resident cases three weeks after the first clinic, compared to a 21% decline among non-vaccinated nursing homes located in the same county. Similarly, new staff cases declined by 33% in vaccinated nursing homes compared to 18% in non-vaccinated facilities.